The present invention relates generally to mechanical gauge instruments, and in particular to a display device and wireless communication circuit for a mechanical gauge instrument.
Mechanical gauge instruments, such as dial pressure gauges and temperature gauges, are used throughout industry as a simple and reliable means to indicate a process parameter, such as pressure or temperature. Such devices are often used as a last resort mechanical back-up to the more accurate electronic process transmitters that provide process information to a control and monitoring system. A feature of such mechanical gauge instruments, in addition to their mechanical simplicity, is their inherently self-powered operation. For example, a Bourdon tube moves in direct response to a pressure change, thus providing the mechanical energy necessary to move a mechanical indicator, such as a dial indicator. Similarly, a bimetallic strip moves in direct response to a temperature change to move a mechanical indicator.
Typically, mechanical gauge instruments are monitored by way of a person walking through an industrial plant, reading each of the instruments, and writing down the readings. This method of recording the instrument readings has the potential to expose the person making the recordings to hazardous areas in the industrial plant. In addition, the activity of reading a mechanical gauge and manually recording the reading may lead to significant errors, in addition to those inherent in the mechanical gauge instruments themselves. This activity is also expensive and time consuming.
A better way of safely and accurately providing mechanical gauge instrument readings, while preserving the simple, reliable, and self-powered nature of mechanical gauge instruments is needed.